INFO: task syz-executor:5856 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:18856 pid:5856  tgid:5856  ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 v9fs_evict_inode+0x170/0x320
 evict+0x504/0x9c0
 __dentry_kill+0x209/0x660
 dput+0x19f/0x2b0
 shrink_dcache_for_umount+0xa0/0x170
 generic_shutdown_super+0x67/0x2c0
 kill_anon_super+0x3b/0x70
 v9fs_kill_super+0x4c/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f02c858ff17
RSP: 002b:00007ffe049a9878 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f02c8611c05 RCX: 00007f02c858ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe049a9930
RBP: 00007ffe049a9930 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe049aa9c0
R13: 00007f02c8611c05 R14: 0000000000015909 R15: 00007ffe049aaa00
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/0:1/10:
 #0: ffff88801bf4c548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900000d7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8881091f6198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20
 #3: ffff88803c95f198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
 #4: ffff88802483b160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400
4 locks held by kworker/u8:0/12:
3 locks held by kworker/u10:0/27:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000060fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
1 lock held by dhcpcd/5596:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50
2 locks held by getty/5677:
 #0: ffff8880240ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:2/5680:
 #0: ffff888119a31148 ((wq_completion)btree_node_rewrite){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc90002bdfbc0 ((work_completion)(&a->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff888047d04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220
 #3: ffff888047d26710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0
1 lock held by syz-executor/5856:
 #0: ffff8881076620e0 (&type->s_umount_key#72){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0
4 locks held by udevd/5869:
 #0: ffff8880451f7e80 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10
 #1: ffff88804145f488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0
 #2: ffff888047b38698 (kn->active#33){.+.+}-{0:0}, at: kernfs_seq_start+0x75/0x3c0
 #3: ffff88803c95f198 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0
3 locks held by kworker/u8:4/5890:
 #0: ffff88810b2e8948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000334fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
2 locks held by syz.3.264/7347:
 #0: ffff888047d04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220
 #1: ffff888047d26710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0
4 locks held by bch-reclaim/loo/7365:
 #0: ffff888047d4af68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0
 #1: ffff888047d04398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f4/0xd80
 #2: ffff888047d04740 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x18bd/0x1a40
 #3: ffff888047d26710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0
2 locks held by kworker/u8:5/7684:
2 locks held by syz-executor/7786:
 #0: ffff888107d8a0e0 (&type->s_umount_key#71){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0
 #1: ffffffff8e13f880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570
2 locks held by syz-executor/9584:
 #0: ffffffff8fa3cf38 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250
 #1: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70
1 lock held by syz.3.663/9612:
 #0: ffffffff8f538c48 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:pv_native_safe_halt+0x13/0x20
Code: 53 e7 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 73 67 0e 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 00000282
RAX: f8908661ead07e00 RBX: ffffffff819683c8 RCX: f8908661ead07e00
RDX: 0000000000000001 RSI: ffffffff8d9b8241 RDI: ffffffff8be33880
RBP: ffffffff8de07eb8 R08: ffff88804b032f9b R09: 1ffff110096065f3
R10: dffffc0000000000 R11: ffffed10096065f4 R12: ffffffff8fa39030
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a20
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1c5ac87e20 CR3: 000000011a72c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 default_idle+0x13/0x20
 default_idle_call+0x74/0xb0
 do_idle+0x1e8/0x510
 cpu_startup_entry+0x44/0x60
 rest_init+0x2de/0x300
 start_kernel+0x3a9/0x410
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x143/0x1c0
 common_startup_64+0x13e/0x147
 </TASK>
